1. Field of the Invention
The present invention relates to endoscopic devices, and, more particularly, to a sheath, external to an endoscope, that includes working channels capable of controllable deflection at their distal ends, and to a related method of using the sheath during an endoscopic operation.
2. Background of the Related Art
An endoscope is a flexible medical device for insertion into a body passageway or cavity that enables an operator, positioned at a remote external location, to perform certain surgical procedures at a site internal to the patient""s body. In general, an endoscope includes a long flexible tubular member equipped with, for example, a miniature viewing device, an illumination device, and working channels. The endoscope has a proximal end that remains external to the patient and a distal end having an endoscope tip for insertion into a body cavity of the patient.
A typical endoscope 10 is illustrated in FIG. 1. An illumination device of endoscope 10 typically includes a lens 16 at an endoscope tip 14. Lens 16 is positioned proximate to a viewing device 17. Light emanates from lens 16 to enable viewing device 17 to capture images in the body cavity and electrically or optically transmit the images through a tubular body 13 of endoscope 10 for display at an external monitor. Once viewing the transmitted images, the endoscope operator may insert one or more surgical instruments through working channels 18, 20 to perform an endoscopic procedure at the internal body cavity site. These endoscopic procedures may include, for example, snare resections, injections, or biopsies of particular internal areas of the patient""s body.
Often, these endoscopic procedures require the use of multiple endoscopic instruments working in cooperation, where each instrument inserts through a separate working channel. Because these instruments work in cooperation, their maneuverability at the endoscope tip is critical to the success of the surgical procedure. But, this maneuverability is limited by the diameter constraints of the endoscope tip which, in turn, are dictated by the particular body cavity dimensions of the patient. Endoscope designs have evolved to minimize the diameter of the endoscope tip to limit the discomfort experienced by the patient. These designs, however, have failed to maximize the maneuverability of therapeutic devices at the endoscope tip. For example, the working channel of the conventional endoscope remains coexistent with the endoscope and offers no independent motion in relation to the endoscope. Such a limitation impedes the maneuverability of surgical instruments at the operation site since they are constrained to follow the movement of the endoscope.
With reference once again to FIG. 1, working channels 18, 20 of endoscope 10 are located internal to endoscope 10 positioned in close proximity to one another, and fixed in the endoscope with no independent mobility. In essence, working channels 18, 20 simply provide a passage for the surgical instruments to reach endoscope tip 14. Because working channels 18, 20 are fixed and located in such close proximity to one another, the endoscope operator has limited range of motion over the surgical instruments at the operation site. This limited mobility not only hinders the cooperation between the multiple surgical instruments but also inhibits the potential for advancement into more complex endoscopic procedures.
Consequently, there is a need for an endoscopic device with working channels that, in addition to providing a passage for the surgical instruments, optimizes the mobility of the surgical instruments at the operation site, while maintaining the required dimensional constraints to permit travel of the endoscopic device through the body cavities of the patient.
The advantages and purpose of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The advantages and purpose of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
To attain the advantages and in accordance with the present invention, as embodied and broadly described herein, the controllable endoscopic sheath of the present invention includes a flexible elongated sheath for surrounding an endoscope. The flexible sheath contains a flexible working lumen extending within the sheath and adjacent to the endoscope so as to permit the lumen to move in relation to the endoscope and beyond a distal tip of the endoscope. The flexible working lumen includes a deflectable distal end. The endoscopic sheath also includes a controller device connected to the distal end of the lumen for controlling deflection of the distal end of the lumen.
According to an aspect of the invention, the controller device includes a wire member disposed on the lumen. The wire member possesses a naturally deflected state as well as an elastic memory and returns to its deflected elastic memory once the wire member extends beyond a distal tip of the endoscope. The distal end of the lumen deflects in response to the distal end deflection of the wire member.
In another aspect, the controller device includes a stiffening member disposed alongside the outside of the lumen and adjacent to the endoscope. The lumen further includes a deflectable lumen tip having a naturally deflected state and an elastic memory. The material of the stiffening member possesses sufficient rigidity to impede only the elastic memory of the lumen tip. The lumen tip, once extended beyond the stiffening member, returns to its original deflected position, thus, causing the distal end of the lumen to deflect.
In still another aspect of the invention, the controller device includes a flexible extension disposed on the lumen at a distal end. The flexible extension attaches to a flexible elongated member that extends along the lumen from the proximal to the distal end of the lumen. The elongated member eccentrically attaches to the flexible extension. The proximal pulling of the elongated member shortens the corresponding length of the elongated member eccentrically attached to the flexible extension and causes the flexible extension to deflect. In response to this deflection, the distal end of the lumen deflects.
The method for using the controllable endoscopic sheath of the present invention in an endoscopic procedure includes inserting an endoscopic device into a body cavity, the endoscopic device having an endoscope, a flexible elongated sheath surrounding the endoscope, and a flexible lumen extending with the sheath and adjacent to the endoscope for containing a surgical tool. Maneuvering the endoscopic device through the body cavity and proximate to an operation site. Once arriving proximate to the operation site, extending a distal end of the lumen beyond a distal tip of the endoscope. And deflecting the extended distal end of the lumen to maneuver the surgical tool.
According to an aspect of the invention, the endoscopic device further includes a wire member having a naturally deflected state as well as an elastic memory and disposed adjacent to the lumen. For such an endoscopic device, the deflecting step includes extending the wire member beyond the distal tip of the endoscope.
In another aspect, the endoscopic device includes a lumen having a naturally deflected state and elastic memory at the distal end. For such an endoscopic device, the deflecting step includes extending a stiffening member beyond the distal tip of the endoscope, where the stiffening member impedes the distal end of the lumen from retaining its naturally defected state.
In still another aspect of the invention, the endoscopic device includes an elongated member disposed on the lumen and eccentrically attached to a flexible extension. The elongated member extends from a proximal end of the lumen to a point proximate the distal end of the lumen and the flexible extension resides at the distal end of the lumen. For such an endoscopic device, the deflecting step includes retracting the elongated member from the proximal end to shorten the distal end of the elongated member and deflect the flexible extension.
Additional advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.